Balanced cut-off valve



(No Model.) 4 Sheets-Sheet 1.-

J. T. CASE.

. BALANCED OUT-OPP VALVE. No. 441,092. Patented Nov. 18, 1890.

(No Model.) 4 Sheets-Sheet 2.

J. T. CASE.

BALANCED GUT-OFF VALVE.

No'. 441,092. P-aJtentedNov. 18-, 1890.

1 PETERS oo mwuvmo msnmarcn n c (No Model.) 4 Sheets-Sheet 3.

J. T. CASE.

BALANGED GUT-OFF VALVE. No. 441,092. Patented N07. 18, 1890.

[III/Ill 1 ala/M644 //7 1/5 far (No Model.) 4-S he tsSheet 4' J. T.CASE. BALANCED GUT-OFF VALVE.

No. 441,092. Patented Nov. 18, 1890.

Av va/7hr. v I

UNITED STATES ATENT OFFICE.

JOEL T. CASE, OF BRISTOL, CONNECTICUT.

BALANCED CUT-OFF VALVE.

SPECIFICATION forming part of Letters Patent No. 441,092, dated November18, 1890. Application filed October 30, 1889. Serial No. 328,627- (Nomodel.)

To all whom it may concern.-

Be it known that I, JOEL T. CAsE,a citizen of the United States,residing at Bristol, in the county of Hartford and State of Connectiout,have invented certain new and useful Improvements in Balanced Cut OffValves for Steam-Engines, of which the following is a specification.

My invention relates to improvements in balanced cut-off Valves forsteam-engines; and the objects of my improvement are simplicity andeconomy in construction and efficiency in operation.

In the accompanying drawings, Figure 1 is a front elevation of an enginehaving my balanced cut-off valve. Fig. 2 is a side elevation of the samewith the shaft and eccentricsleeve in section. Fig. 3 is a Verticalsection of parts on the line a: a: of Fig. 1. Fig. 4 is a like view onthe line 3 y of Fig. 1. Fig. 5 is a horizontal section,partly inplanview, on line 5 .2 of Fig. 3. Fig. 6 is a like section on the same.line, showing the valve-chamber with the valve removed; and Fig. 7 is aver tical section of the upper part of my engine on the line 00 0c ofFig. 1.

The general form of the engine is the same as that patented to meDecember 18, 1888, No. 394,675. It is shown most clearly in Fig. 7, inwhich 40 designates a sleeve through which the piston-rod 41 works inoperating the piston 42 and its oscillating cylinder 43. The live-steamport 20 22 and exhaust-steam ports 43 44 are on opposite sides of thecylinder and are opened and closed by the oscillating movement of saidcylinder, as in my aforesaid patent, so that when live steam enters theupper end of the cylinder through the port 20 it exhausts at the lowerend through the port 44, and when live steam enters the lower end of thecylinder through the port 22 it exhausts at the upper end through theport 43.

A designates the case or frame, B the crankshaft, and C the governormounted on said shaft. This governor may be of any ordinary constructionand provided with a sleeve 7 and eccentric 8, the same as in othergovernors. The live-steam chest D at the upper part of the engine isenlarged on one side to make room for the rotary cutofi valve E. Thisvalve is provided with a projecting spindle 9,

to the outer end of which I attach acrank 10, and I connect said crankwith the eccentric 'of the governor by the pitman 11, whereby saideccentric will partially rotate the cut off valve a given distance ateach revolution of the shaft B, the time of which movement of said valverelatively to the opening and closing of the valves at the ends of thecylinder will be varied by the governor according to the variation inspeed of the crankshaft.

The live-steam chest D is supplied through the pipe 12, and theexhaust-steam passes out from the exhaust-steam'chest N on the oppositeside through the pipe 13. Between the live and exhaust steam chests isthe cylinderchamber, one side of which is shown in Figs. 3 and 4 at 14and the whole chamber in Fig. 7, the flat sides of said chamber beingcovered by the caps 15.

In the wall of the steam-chest D, I bore a tapering hole, as avalve-chamber, for the cutoff valve E, and close the ends of this holeby screw-plugs 16 and 17. The plug 16 is provided witlr a pointed screw18 for centering the inner end of the valve-spindle 9 and for adjustingthe valve, While the body of said spindle passes outwardly through acentral hole in the plug 17. The valve E is a hollow tubular valve openat one end and has its periphery fitted to the bore of the chamber thatreceives it. Two openings 19 are made through its shell on oppositesides, as shown. The ports 20 22, which open into the cylinder chamber14, for the opposite ends ofgthe cylinder lead to and open into thevalve-chamber, and no steam can enter them except that which passesthrough the cut-off valve. I form two balancing-chambers or depressions21 23 in the wall of the valve-chamber at points nearly opposite thatend of the ports 2O 22 that open into said valve-chamber, as shown.These balancing-chambers are closed at each end; but I make a passage24, that leads from the port 20 to its opposite balanc ing-chamber 21,and a passage 25, that leads from the port 22 to its oppositebalancingchamber 23. A convenient way to form the passages 24 and 25 isto drill two parallel horizontal holes into the desired port and chamberto be connected and then connect said horizontal holes by drilling avertical hole running into both of the horizontal holes, as clearlyshown in Figs. 3 and 4, and then stop the outer ends of said drilledholes by plugs 26. That end of thevalve-chamber in which the open end ofthe valve E is located is provided with a passage-way 27, that opensinto the interior of the steamchest D.

Steam entering the live steam chest D through the pipe 12 comes into theopen end of the cut-off valve E through the passage Way 27. As the valvepartially rotates it presents one of its side openings 19 successivelyto the ports 20 and 22, so that the steam passes through them first toone end of the cylinder and then to the other. The steam is cutofi fromboth ports when the valve is in the position shown in Figs. 3, 4, and 5,the solid portions of the valve-periphery covering said ports. When theeccentric operates the valve to bring one of the openings 19 in front ofthe port 20 and the opposite opening 19 in front of thebalancing-chamber 21, the steam can pass from said valve in bothdirection sthat is to say, directly into the port 20 on one side andindirectly into the port 20 through the balancing-chamber and passage25. .At the same time the solid portions of the valve E will be in frontof the port 22 and its opposite balancing-chamber 23, so as to closethem, which port and chamber are connected by the passage 25, as shownin Fig. 3, whereby all the pressure of the steam under its expansiveforce within said port and balancing-chamber will be exerted equallyupon both sides and perfectly balance the valve, so that it maypartially rotate without much friction. In like manner, when the valveopens to the port 22 and its opposite balancing-chamber 23, the solidportions of the wall are in front of and out oif communication betweenthe interior of the valve and the port 20 and balancing-chamber 21,which port and chamber are connected by the passage 24, so that thepressure upon opposite sides of the valve is balanced.

In a prior application filed by me February 14, 1888, Serial No.263,973,I have shown, described, and claimed an engine having a pistonand oscillating cylinder with valves consisting of a movable part, whichrocks with the oscillating movement of the cylinder and is provided withradial ports, and a stationary. part having radial ports, in combinationwith a cut-off in a steam-passage leading to said ports and a governorconnected with said cut-off for varying the time of operating itrelatively to the opening and closing of the valves proper, andtherefore I do not claim ferred to in said prior application,

the same in this application, although the present engine, cutoff, andgovernor constitute the same combination.

My improved cut-off valve is of a different construction and isbalanced, and the engine proper, although of the same class as that reisof the improved form shown and described in my prior patent hereinbeforenamed.

I claim as my invention- 1. In an engine, the combination of thesteam-chest having a valve-chamber and passage 27 leading from theinterior of said steamchest to one end of said chamber, the ports 20 and22, opposing balancing-chambers 21 23 and connecting-passages, and thevalve E,

of a tubular form, open at the end and pro videdlwith side openings ofless breadth than the distance between the ports 20 and 22, and twosolid portions, each of abreadth sufficient to cover one of said portsand the space between the two, substantially as described, and for thepurpose specified.

2. In an engine having a rotary cutoff valve, the steam-chest havingthe. valve-chamber, the ports 20 22, balancing-chambers 21 23, and thepassages 24 25, extending in an angular form from each port to itsopposing chamber, whereby said passages may be formed by drilling andplugging the outer open ends, substantially as described, and for thepurpose specified.

3. In an engine, the combination of a steamchest, a valve-chamber havingports leading to the respective ends of the cylinder, a balanced cut-offvalve fitted within said valvechamber, an eccentric for oscillating saidoutoff valve to alternately cut off and open said ports, and a governorconnected with said outoff valve to vary its time of action,substantially as described, and for the purpose specified.

4;. In an engine, the combination of the steam-chest havinga-valve-chamber and passage 27 leading from the interior of saidsteamchest to one end of said chamber, the ports, opposingbalancing-chambers, and connecting-passages, the valve E, of a tubularform, open at the end and provided with side openings, the spindle 9, onwhich said valve is mounted, and the screw 18, hearing on the end ofsaid spindle, substantially as described, and for the purpose specified.

JOEL '1. CASE.

